Measurement Of Oscillation Parameters Research Articles

Non-standard neutrino interactions mediated by a light scalar at DUNE

We investigate the effect on neutrino oscillations generated by beyond-the-standard-model interactions between neutrinos and matter. Specifically, we focus on scalar-mediated non-standard interactions (NSI) whose impact fundamentally differs from that of vector-mediated NSI. Scalar NSI contribute as corrections to the neutrino mass matrix rather than the matter potential and thereby predict distinct phenomenology from the vector-mediated ones. Similar to vector-type NSI, the presence of scalar-mediated neutrino NSI can influence measurements of oscillation parameters in long-baseline neutrino oscillation experiments, with a notable impact on CP measurement in the case of DUNE. Our study focuses on the effect of scalar NSI on neutrino oscillations, using DUNE as an example. We introduce a model-independent parameterization procedure that enables the examination of the impact of all non-zero scalar NSI parameters simultaneously. Subsequently, we convert DUNE’s sensitivity to the NSI parameters into projected sensitivity concerning the parameters of a light scalar model. We compare these results with existing non-oscillation probes. Our findings reveal that the region of the light scalar parameter space sensitive to DUNE is predominantly excluded by non-oscillation probes, especially when considering all nonzero parameters simultaneously for DUNE.

Expanding neutrino oscillation parameter measurements in NOvA using a Bayesian approach

NOvA is a long-baseline neutrino oscillation experiment that measures oscillations in charged-current νμ→νμ (disappearance) and νμ→νe (appearance) channels, and their antineutrino counterparts, using neutrinos of energies around 2 GeV over a distance of 810 km. In this work we reanalyze the dataset first examined in our previous paper [] using an alternative statistical approach based on Bayesian Markov chain Monte Carlo. We measure oscillation parameters consistent with the previous results. We also extend our inferences to include the first NOvA measurements of the reactor mixing angle θ13, where we find 0.071≤sin22θ13≤0.107, and the Jarlskog invariant, where we observe no significant preference for the CP-conserving value J=0 over values favoring CP violation. We use these results to examine the effects of constraints from short-baseline measurements of θ13 using antineutrinos from nuclear reactors when making NOvA measurements of θ23. Our long-baseline measurement of θ13 is shown to be consistent with the reactor measurements, supporting the general applicability and robustness of the Pontecorvo-Maki-Nakagawa-Sakata framework for neutrino oscillations. Published by the American Physical Society 2024

Impact of errors in the magnetic field measurement on the precision determination of neutrino oscillation parameters at the proposed ICAL detector at INO

The magnetised iron calorimeter (ICAL) detector proposed at the India-based Neutrino Observatory will be a 51 kton detector made of 151 layers of 56 mm thick soft iron with 40 mm air gap in between where the RPCs, the active detectors, will be placed. The main goal of ICAL is to make precision measurements of the neutrino oscillation parameters, especially of the neutrino mass ordering, using the atmospheric neutrinos as source. The charged current interactions of the atmospheric muon neutrinos and anti-neutrinos in the detector produce charged muons. The magnetic field, with a maximum value of ∼ 1.5 T in the central region of ICAL, is a critical component since it will be used to distinguish the charges and determine the momentum and direction of these muons. It is difficult to measure the magnetic field inside the iron. The existing methods can only estimate the internal field and hence will be prone to error. This paper presents the first simulations study of the effect of errors in the measurement of the magnetic field in ICAL on its physics potential, especially the neutrino mass ordering and precision measurement of oscillation parameters in the 2–3 sector. The study is a GEANT4-based analysis, using measurements of the magnetic field at the prototype ICAL detector. We find that there is only a small effect on the determination of the mass ordering. While local fluctuations in the magnetic field measurement are well-tolerated, calibration errors must remain well within 5% to retain good precision determination of the parameters sin2 θ 23 and Δm 2 32.

Simulation analysis with rock muons from atmospheric neutrino interactions in the ICAL detector at the India-based Neutrino Observatory

The proposed magnetized Iron CALorimeter detector (ICAL) to be built in the India-based Neutrino Observatory (INO) laboratory aims to study atmospheric neutrinos and its properties such as precision measurements of oscillation parameters and the neutrino mass hierarchy. High energy charged current (CC) interactions of atmospheric neutrinos with the rock surrounding the detector produce so-called “rock muons” along with hadrons. While the hadron component of these events are absorbed in the rock itself, the rock muons traverse the rock and are detected in the detector. These rock muon events can be distinguished from cosmic muons only in the upward direction and can provide an independent measurement of the oscillation parameters. A simulation study of these events at the ICAL detector shows that, although reduced in significance compared to muons produced in direct CC neutrino interactions with the detector, these events are indeed sensitive to the oscillation parameters, achieving a possible 1σ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1\\sigma $$\\end{document} precision of 10% and 27% in determining Δm322\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\varDelta m_{32}^2$$\\end{document} and sin2θ23\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sin ^2\ heta _{23}$$\\end{document}, respectively. Hence a combination of the standard atmospheric neutrino analysis which is the main goal of ICAL, with these rock muon events, will improve the precision reach of ICAL for these parameters.

Deferred Optical Photon simulation for the JUNO experiment

The Jiangmen Underground Neutrino Observatory (JUNO) is designed to determine the neutrino mass ordering and precisely measure oscillation parameters. It is being built in South China at a depth of 700 m underground and comprises a central detector, water Cerenkov detector and top tracker. The central detector is designed to detect anti-neutrinos with an energy resolution of 3% at 1 MeV, using a 20 kt liquid scintillator target with 17,612 20-inch PMTs and 25,600 3-inch PMTs. The scintillator provides a light yield of approximately 10,000 photons per MeV. Monte Carlo simulation is a crucial tool for developing an understanding of detector performance, requiring the production of large samples of background processes with optical photons. Simulation of large numbers of optical photons with Geant4 is computationally challenging for both processing time and memory resources. In order to optimize resource usage, a deferred optical photon simulation workflow is proposed and implemented using Geant4 classes. The key idea is to simulate events initially without optical photons, only performing the optical photon simulation when user specified criteria are met.In this contribution, the design and the implementation of the deferred optical photon simulation will be presented. Optical simulation comprises generation of photons and propagation through the detector implementing optical physics processes including reflection, refraction, scattering and absorption. Instead of generating the optical photons at each step by Geant4 immediately, the necessary data to generate optical photons at each step are collected, which is termed GenStep. At the end of each event, user specified criteria determines if the optical photon simulation is performed using a class called G4OPSimulator. The class G4OPSimulator implements a customized simulation workflow, based on Geant4 internal classes including G4TrackingManager and G4StackManager. The simulator passes references to the collected GenStep objects to customized Scintillation and Cerenkov processes which generate the optical photons in G4Track objects. As a track could be absorbed and re-emitted, the secondaries will be retrieved from the G4TrackingManager and pushed to the G4StackManager. The performance of the simulator will be presented. The technique of deferred optical photon simulation can be applied to all event types and it is expected to be particularly beneficial with rare processes. Especially the events must be selected during the detector simulation at runtime, instead of the event generation. An application of the technique to the simulation of such events will be shown.

Vector leptoquark U_3 and CP violation at T2K, NOvA experiments

In the current epoch of neutrino physics, many experiments are aiming for precision measurements of oscillation parameters. Thus, various new physics scenarios which alter the neutrino oscillation probabilities in matter deserve careful investigation. In this context, we study the effect of a vector leptoquark which induces non-standard neutrino interactions (NSI) that modify the oscillation probabilities of neutrinos in matter. We show that such interactions provide a relatively large value of NSI parameter varepsilon _{e mu }. Considering this NSI parameter, we successfully explain the recent discrepancy between the observed delta _{CP} results of T2K and NOvA.

Quantifying Effects of Final-State Interactions on Energy Reconstruction in DUNE

In neutrino-nucleus interactions, the particles produced at the primary vertex may be different from the particles observed in the final state. This is due to the effect of final-state interactions (FSI) on the particles during their transport in the nuclear matter to reach the detector (final state) after their production at the primary vertex. In this report, the energy reconstruction is done for charged current quasielastic (CCQE) and charged current resonance (CCRES) scatterings on the event-by-event basis using the calorimetric method, and NuWro and GENIE simulation tools. In addition, the percentage of fake events in CCQE and CCRES interactions is presented. It is found that the percentage of fake events is more than 50% for both CCQE and CCRES processes for both the generators, if we apply the condition for the signal events that the particles observed in the final state should be the same as the particles produced at the primary vertex. Based on our definition of signal events, the reconstructed energy and number of fake events may change, and this influences the measurement of oscillation parameters in long-baseline experiments like DUNE.

The JUNO experiment and its electronics readout system

The main goal of the Jiangmen Underground Neutrino Observatory (JUNO) under construction in China is to determine the neutrino mass hierarchy and to measure oscillation parameters to the sub-percent level. The detector consists of 20 ktons of liquid scintillator instrumented by 17612 20-inch photo-multiplier tubes, and 25600 3-inch small PMTs, with photo-cathode coverage of 77%. The electronics system is separated into two main parts. The front-end system, sitting under water, performs analog signal processing. The back-end electronics system, sitting outside water, consists of the DAQ and the trigger. The current production status of the experiment as well as the design of the electronics system will be reported in the presentation.

CPT violation in neutrino oscillations

In this talk I consider CPT violating neutrino oscillations in its most general form, i.e. assuming different oscillation parameters for neutrinos and antineutrinos. In this scenario the measurement of oscillation parameters is much more difficult than in the standard case. I will discuss the implication on the recent CP measurements in T2K and NOυA, and also discuss how well current experiments can bound different neutrino and antineutrino parameters. Finally, I will discuss how well the upcoming DUNE experiment might improve the current bounds.

Direction reconstruction using a CNN for GeV-scale neutrinos in IceCube

The IceCube Neutrino Observatory is designed to observe neutrinos interacting deep within the South Pole ice sheet. It consists of 5160 digital optical modules, which are arrayed over a cubic kilometer from 1450 m to 2450 m depth. At the lower center of the array is the DeepCore subdetector. It has a denser configuration which lowers the observable energy threshold to about 10 GeV and creates the opportunity to study neutrino oscillations with low energy atmospheric neutrinos. A precise reconstruction of neutrino direction is critical in the measurements of oscillation parameters. In this contribution, I will discuss a method to reconstruct the zenith angle of 10-GeV scale events in IceCube using a convolutional neural network and compare the result to that of the current likelihood-based reconstruction algorithm.

Physics potential of the combined sensitivity of T2K-II, NOνA extension, and JUNO

Leptonic \textit{CP} violation search, neutrino mass hierarchy determination, and the precision measurement of oscillation parameters for a unitary test of the leptonic mixing matrix are among the major targets of the ongoing and future neutrino oscillation experiments. The work explores the physics reach for these targets by around 2027, when the third generation of the neutrino experiments starts operation, with a combined sensitivity of three experiments: T2K-II, NO$\nu$A extension, and JUNO. It is shown that a joint analysis of these three experiments can conclusively determine the neutrino mass hierarchy. Also, at certain values of \emph{true} \dcp, it provides closely around a $5\sigma$ confidence level (C.L.) to exclude \textit{CP}-conserving values and more than a $50\%$ fractional region of \emph{true} $\delta_{\text{CP}}$ values can be explored with a statistic significance of at least a $3\sigma$ C.L. Besides, the joint analysis can provide unprecedented precision measurements of the atmospheric neutrino oscillation parameters and a great offer to solve the $\theta_{23}$ octant degeneracy in the case of nonmaximal mixing.

Investigation of the Influence of Dynamic Loads of Industrial Equipment on the Occurrence of Prolonged Yielding of their Foundation Soils

The parameters of oscillations of the foundations and structures of the dynamic equipment of the new production workshop located in the Kharkiv region were experimentally investigated. For this purpose, appropriate measurements of the amplitude of oscillations in the vertical and orthogonal horizontal directions were performed. To compare the parameters of the amplitudes of forced oscillations and determine the damping properties of the applied rubber spacers placed between the frame and the slides, as well as the quenching effect of the foundation massif, several measurements of oscillation parameters were performed at the locations mentioned above. The amplitude of oscillations of the vertical component of the vibration load on different sides of the rubber dampers was reduced by 2-3 times, the horizontal component was completely attenuated. It was also established that there was no transmission of vibrations to the foundations of the production workshop. The safety of the measured parameters of oscillations from the point of view of long significant unstabilized subsidence of the foundations, both equipment and building, was determined. Recommendations for monitoring are given from the point of view of the possible deterioration of the properties of the used rubber dampers over time.

Research on the measurement of connecting bars’ axial force of JUNO central detector

The Jiangmen Underground Neutrino Observatory (JUNO) is a multipurpose neutrino experiment designed to determine neutrino mass hierarchy and precisely measure oscillation parameters and study the solar neutrino, supernova neutrino, geo-neutrino, etc. JUNO’s central detector (CD) has 20 kilo-ton liquid scintillator as target mass, which is contained by a huge acrylic sphere with the inner diameter of 35.4 m, and the acrylic sphere is supported by a stainless steel structure through 590 connecting bars. Part of the connecting bars bear pull force and the other bars bear push force. There is a direct relationship between the stress of connecting bars and that of acrylic sphere. For the installation process of the CD, the pretightening force and axial force of the connecting bars should be monitored with accuracy, and for the filling process and running condition, the precise measurement of axial force can indicate the safety of structure of the CD. Statistical method was used to evaluate the performance of measurement schemes, and 4-fiber Bragg grating measurement scheme was determined to be the final scheme, which can get the measurement uncertainty better than 0.7 kN. Performance of different measurement schemes are discussed in detail, and some related finite element analysis and evaluation method are also introduced in this paper.

Enhancing sensitivity to non-standard neutrino interactions at INO combining muon and hadron information

In this paper, we explore the impact of flavor violating neutral current non-standard interaction (NSI) parameter varepsilon _{mu tau } in the oscillation of atmospheric neutrinos and antineutrinos separately using the 50 kt magnetized ICAL detector at INO. We find that due to non-zero varepsilon _{mu tau }, nu _mu rightarrow nu _mu and {bar{nu }}_mu rightarrow {bar{nu }}_mu transition probabilities get modified substantially at higher energies and longer baselines, where vacuum oscillation dominates. We demonstrate for the first time that by adding the hadron energy information along with the muon energy and muon direction in each event, the sensitivity of ICAL to the NSI parameter varepsilon _{mu tau } can be enhanced significantly. The most optimistic bound on varepsilon _{mu tau } that we obtain is -,,0.01< varepsilon _{mu tau } < 0.01 at 90% C.L. using 500 ktcdot yr exposure and considering E_mu , cos theta _mu , and E'_{mathrm{had}} as observables in their ranges of [1, 21] GeV, [− 1, 1], and [0, 25] GeV, respectively. We discuss for the first time the importance of the charge identification capability of the ICAL detector to have better constraints on varepsilon _{mu tau }. We also study the impact of non-zero varepsilon _{mu tau } on mass hierarchy determination and precision measurement of oscillation parameters.

Prospects of measuring oscillated decay-at-rest neutrinos at long baselines

In addition to the next generation of beam-based neutrino experiments and their associated detectors, a number of intense, low-energy neutrino production sources from decays at rest will be in operation. In this work, we explore the physics opportunities with decay-at-rest neutrinos for complementary measurements of oscillation parameters at long baselines. The J-PARC Spallation Neutron Source, for example, will generate neutrinos from a variety of decay-at-rest (DAR) processes, specifically those of pions, muons, and kaons. Other proposed sources will produce large numbers of stopped pions and muons. We demonstrate the ability of the upcoming Hyper-Kamiokande experiment to detect the monochromatic kaon decay-at-rest neutrinos from J-PARC after they have traveled several hundred kilometers and undergone oscillations. This measurement will serve as a valuable cross-check in constraining our understanding of neutrino oscillations in a new regime of neutrino energy and baseline length. We also study the expected event rates from pion and muon DAR neutrinos in liquid argon and water detectors and their sensitivities to the charge-parity- ($CP$) violating phase ${\ensuremath{\delta}}_{\mathit{CP}}$.

Jupyter-based service for JUNO analysis

The JUNO (Jiangmen Underground Neutrino Observatory) is designed to determine the neutrino mass hierarchy and precisely measure oscillation parameters. The estimated data volume of raw data is about 2 PB/year. The event rate of reactor anti-neutrinos is about 60/day, while the event rate of background is about O(10) Hz. The challenge is the event correlation during the analysis, where the background events could not be discarded. In order to use big data techniques to search for rare events, a Jupyter-based interactive service is developed for JUNO analysis. In this paper, an overview of this service is presented. The infrastructure is based on Jupyter and Kubernetes, which provides the user interface and resource management. In order to integrate the data processing framework and big data techniques, an index file is used as an intermediate file, which points to the interested events. Data processing framework SNiPER is used to select the candidate of neutrino signals and produce the index file. Apache Spark is then used to process such index file repeatedly with data cached in memory. With the index file produced from Spark and the complete event data files, SNiPER is used to process them and produce the final physics result. At the end of paper, the test-bed is presented and the testing result is shown.

Development of the JUNO Conditions Data Management System

The Jiangmen Underground Neutrino Observatory (JUNO) experiment is designed to determine the neutrino mass hierarchy and precisely measure oscillation parameters with an unprecedented energy resolution of 3% at 1 MeV. It is composed of a 20 kton liquid scintillator central detector equipped with 18000 20-inch PMTs and 25000 3-inch PMTs, a water pool with 2000 20-inch PMTs, and a top tracker. Conditions data, coming from calibration and detector monitoring, are heterogeneous, different type of conditions data has different write rates, data format and data volume. JUNO conditions data management system (JCDMS) is developed to homogeneously treat all these heterogeneous conditions data in order to provide easy management and convenient access with both Restful API and web interfaces, support good scalability and maintenance for long time running. The paper describes the status and development of JCDMS including the data model, workflows, interfaces, data caching and performance of the system.

Status of JUNO Simulation Software

The JUNO (Jiangmen Underground Neutrino Observatory) experiment is a multi-purpose neutrino experiment designed to determine the neutrino mass hierarchy and precisely measure oscillation parameters. It will be composed of a 20k ton liquid scintillator (LS) central detector equipped with about 18000 20-inch photon-multipliers (PMTs) and 25000 3-inch PMTs, a water Cherenkov detector with about 2000 20-inch PMTs, and a top tracker. Monte-Carlo simulation is a fundamental tool for optimizing the detector design, tuning reconstruction algorithms, and performing physics study. The status of JUNO simulation software will be presented, including generator interface, detector geometry, physics processes, MC truth, pull-mode electronic simulation.

Thermal reliability analysis of the central detector of JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a multipurpose neutrino experiment designed to determine neutrino mass hierarchy, precisely measure oscillation parameters and study solar neutrinos, supernova neutrinos and geo-neutrinos, etc. The central detector (CD) of JUNO has 20,000 tons liquid scintillator as target mass, which contains inside a huge acrylic sphere with inner diameter of 35.4 m, supported by a stainless steel structure. The whole structure of CD will be installed inside a cylindrical water pool, and the acrylic sphere will be submerged in the center of water pool. The operating temperature of CD is designed to be 21 °C as long as over 20 years, which is determined by the mechanical requirement of the structure and physics consideration. For this operating temperature, a special cooling system will be used to maintain the temperature inside the water pool. The main structure of CD is composed of acrylic and stainless steel, and they have much different thermal expansion coefficients, strengths and life times. Change in temperature may affect the safety of CD. As part of reliability analysis, the effect of cooling system failure on the CD is considered, and finite element method is used in our thermal calculation. In this article, the temperature fields before and after cooling system failure are calculated and analyzed, and the temperatures of different locations of water pool after cooling system failure are compared and discussed in detail.

Results on Neutrino and Antineutrino Oscillations from the NOvA Experiment

NOvA is a two-detector long-baseline neutrino oscillation experiment using Fermilab’s 700 kW NuMI muon neutrino beam. With a total exposure of 8.85×1020 +12.33×1020 protons on target delivered to NuMI in the neutrino + antineutrino beam mode (78% more antineutrino data than in 2018), the experiment has made a 4.4q-significant observation of the ve appearance in a vм beam, measured oscillation parameters |Δm232|, sin2O23, and excluded most values near бCP = п/2 for the inverted neutrino mass hierarchy by more than 3q.